The mobile body such the vehicle or the ship has instrument device displaying a variety of information metered by various metering devices. For example, the PTL 1 discloses that design of such instrument plate of the metering devices installed in the vehicle is made alterable in these metering devices.
The conventional instrument disclosed in the PTL is provided with a main microprocessor for controlling whole instrument, and a GDC (Graphic Display Control) microprocessor for controlling display device as a sub microprocessor.
The main microprocessor is provided with an interface capable of communicating with external, and a non-volatile rewritable memory such as flash memory, and controls motion of an indicator and the like, or instructs the GDC microprocessor based on control program stored in the memory in order to display a variety of vehicle information inputted from the interface.
The GDC microprocessor is provided with a non-volatile rewritable memory in which image data to be displayed on the display devise is stored, and reads the image data from the memory to display based on instructions from the main microprocessor.